1. Field
This invention relates to bitumen processing and more particularly is related to heating bituminous froth using inline steam injection.
2. Description of Related Art
In extracting bitumen hydrocarbons from tar sands, one extraction process separates bitumen from the sand ore in which it is found using an ore washing process generally referred to as the Clark hot water flotation method. In this process, a bitumen froth is typically recovered at about 150° F. and contains residual air from the flotation process. Consequently, the froth produced from the Clark hot water flotation method is usually described as aerated bitumen froth. Aerated bitumen froth at 150° F. is difficult to work with. It has similar properties to roofing tar. It is very viscous and does not readily accept heat. Traditionally, processing of aerated bitumen froth requires the froth to be heated to 190° F. to 200° F. and de-aerated before it can move to the next stage of the process.
Heretofore, the aerated bitumen froth is heated and de-aerated in large atmospheric tanks with the bitumen fed in near the top of the vessel and discharged onto a shed deck. The steam is injected below the shed deck and migrates upward, transferring heat and stripping air from the bitumen as they contact. The method works but much of the steam is wasted and bitumen droplets are often carried by the exiting steam and deposited on nearby vehicles, facilities and equipment.